After the call of the isatty() we check its result twice in the
open_terminal(). There are no sense to check result of isatty() that
it is less than zero and return -errno, because as described in
documentation:
isatty() returns 1 if fd is an open file descriptor referring to a
terminal; otherwise 0 is returned, and errno is set to indicate the
error.
So it can't be less than zero.
This changes the semantics a bit: before, SYSTEMD_COLORS= would be treated as
"yes", same as SYSTEMD_COLORS=xxx and SYSTEMD_COLORS=1, and only
SYSTEMD_COLORS=0 would be treated as "no". Now, only valid booleans are treated
as "yes". This actually matches how $SYSTEMD_COLORS was announced in NEWS.
When started by the kernel, we are connected to the console, and we'll set TERM
properly to some value in fixup_environment(). We'll then enable or disable
colors based on the value of $SYSTEMD_COLORS and $TERM.
When reexecuting, TERM should be already set, so we can use this value.
Effectively, behaviour is the same as before affd7ed1a was reverted, but instead
of reopening the console before configuring color output, we just ignore what
stdout is connected to and decide based on the variables only.
A masked unit is listed in Also=:
$ systemctl cat test1 test2
→# /etc/systemd/system/test1.service
[Unit]
Description=test service 1
[Service]
Type=oneshot
ExecStart=/usr/bin/true
[Install]
WantedBy=multi-user.target
Also=test2.service
Alias=alias1.service
→# /dev/null
$ systemctl --root=/ enable test1
(before)
Created symlink /etc/systemd/system/alias1.service → /etc/systemd/system/test1.service.
Created symlink /etc/systemd/system/multi-user.target.wants/test1.service → /etc/systemd/system/test1.service.
The unit files have no installation config (WantedBy, RequiredBy, Also, Alias
settings in the [Install] section, and DefaultInstance for template units).
This means they are not meant to be enabled using systemctl.
Possible reasons for having this kind of units are:
1) A unit may be statically enabled by being symlinked from another unit's
.wants/ or .requires/ directory.
2) A unit's purpose may be to act as a helper for some other unit which has
a requirement dependency on it.
3) A unit may be started when needed via activation (socket, path, timer,
D-Bus, udev, scripted systemctl call, ...).
4) In case of template units, the unit is meant to be enabled with some
instance name specified.
(after)
Created symlink /etc/systemd/system/alias1.service → /etc/systemd/system/test1.service.
Created symlink /etc/systemd/system/multi-user.target.wants/test1.service → /etc/systemd/system/test1.service.
Unit /etc/systemd/system/test2.service is masked, ignoring.
Running preset-all on a system installed from rpms or even created
using make install would remove and recreate a lot of symlinks, changing
relative to absolute symlinks. In general relative symlinks are nicer,
so there is no reason to change them, and those spurious changes were
obscuring more interesting stuff.
$ make install DESTDIR=/var/tmp/inst1
$ systemctl preset-all --root=/var/tmp/inst1
(before)
Removed /var/tmp/inst1/etc/systemd/system/network-online.target.wants/systemd-networkd-wait-online.service.
Created symlink /var/tmp/inst1/etc/systemd/system/ctrl-alt-del.target → /usr/lib/systemd/system/exit.target.
Removed /var/tmp/inst1/etc/systemd/system/multi-user.target.wants/remote-fs.target.
Created symlink /var/tmp/inst1/etc/systemd/system/multi-user.target.wants/remote-fs.target → /usr/lib/systemd/system/remote-fs.target.
Created symlink /var/tmp/inst1/etc/systemd/system/multi-user.target.wants/machines.target → /usr/lib/systemd/system/machines.target.
Created symlink /var/tmp/inst1/etc/systemd/system/sockets.target.wants/systemd-journal-remote.socket → /usr/lib/systemd/system/systemd-journal-remote.socket.
Removed /var/tmp/inst1/etc/systemd/system/sockets.target.wants/systemd-networkd.socket.
Created symlink /var/tmp/inst1/etc/systemd/system/sockets.target.wants/systemd-networkd.socket → /usr/lib/systemd/system/systemd-networkd.socket.
Removed /var/tmp/inst1/etc/systemd/system/getty.target.wants/getty@tty1.service.
Created symlink /var/tmp/inst1/etc/systemd/system/getty.target.wants/getty@tty1.service → /usr/lib/systemd/system/getty@.service.
Created symlink /var/tmp/inst1/etc/systemd/system/multi-user.target.wants/systemd-journal-upload.service → /usr/lib/systemd/system/systemd-journal-upload.service.
Removed /var/tmp/inst1/etc/systemd/system/sysinit.target.wants/systemd-timesyncd.service.
Created symlink /var/tmp/inst1/etc/systemd/system/sysinit.target.wants/systemd-timesyncd.service → /usr/lib/systemd/system/systemd-timesyncd.service.
Removed /var/tmp/inst1/etc/systemd/system/multi-user.target.wants/systemd-resolved.service.
Created symlink /var/tmp/inst1/etc/systemd/system/multi-user.target.wants/systemd-resolved.service → /usr/lib/systemd/system/systemd-resolved.service.
Removed /var/tmp/inst1/etc/systemd/system/multi-user.target.wants/systemd-networkd.service.
Created symlink /var/tmp/inst1/etc/systemd/system/multi-user.target.wants/systemd-networkd.service → /usr/lib/systemd/system/systemd-networkd.service.
(after)
Removed /var/tmp/inst1/etc/systemd/system/network-online.target.wants/systemd-networkd-wait-online.service.
Created symlink /var/tmp/inst1/etc/systemd/system/ctrl-alt-del.target → /usr/lib/systemd/system/exit.target.
Created symlink /var/tmp/inst1/etc/systemd/system/multi-user.target.wants/machines.target → /usr/lib/systemd/system/machines.target.
Created symlink /var/tmp/inst1/etc/systemd/system/sockets.target.wants/systemd-journal-remote.socket → /usr/lib/systemd/system/systemd-journal-remote.socket.
Created symlink /var/tmp/inst1/etc/systemd/system/multi-user.target.wants/systemd-journal-upload.service → /usr/lib/systemd/system/systemd-journal-upload.service.
Before, when interating over unit files during preset-all, behaviour was the
following:
- if we hit the real unit name first, presets were queried for that name, and
that unit was enabled or disabled accordingly,
- if we hit an alias first (one of the symlinks chaining to the real unit), we
checked the presets using the symlink name, and then proceeded to enable or
disable the real unit.
E.g. for systemd-networkd.service we have the alias dbus-org.freedesktop.network1.service
(/usr/lib/systemd/system/dbus-org.freedesktop.network1.service), but the preset
is only for the systemd-networkd.service name. The service would be enabled or
disabled pseudorandomly depending on the order of iteration.
For "preset", behaviour was analogous: preset on the alias name disabled the
service (following the default disable policy), preset on the "real" name
applied the presets.
With the patch, for "preset" and "preset-all" we silently skip symlinks. This
gives mostly the right behaviour, with the limitation that presets on aliases
are ignored. I think that presets on aliases are not that common (at least my
preset files on Fedora don't exhibit any such usage), and should not be
necessary, since whoever installs the preset can just refer to the real unit
file. It would be possible to overcome this limitation by gathering a list of
names of a unit first, and then checking whether *any* of the names matches the
presets list. That would require a significant redesign of the code, and be
a lot slower (since we would have to fully read all unit directories to preset
one unit) to so I'm not doing that for now.
With this patch, two properties are satisfied:
- preset-all and preset are idempotent, and the second and subsequent invocations
do not produce any changes,
- preset-all and preset for a specific name produce the same state for that unit.
Fixes#3616.
The parsing functions for [User]TasksMax were inconsistent. Empty string and
"infinity" were interpreted as no limit for TasksMax but not accepted for
UserTasksMax. Update them so that they're consistent with other knobs.
* Empty string indicates the default value.
* "infinity" indicates no limit.
While at it, replace opencoded (uint64_t) -1 with CGROUP_LIMIT_MAX in TasksMax
handling.
v2: Update empty string to indicate the default value as suggested by Zbigniew
Jędrzejewski-Szmek.
v3: Fixed empty UserTasksMax handling.
Rework 17eb9a9ddb a bit.
Let's make sure we don't clobber the input parameter args[1], following our
coding style to not clobber parameters unless explicitly indicated. (in
particular, as we don't want to have our changes appear in the command line
shown in "ps"...)
No functional change.
Inspired from the new logic in nss-systemd let's make sure we don't end up
deadlocking in nss-mymachines either in case dbus-daemon tries to a look up a
name and we want to connect to the bus.
This case is much simpler though, as there's no point in resolving virtual
machine UIDs by dbus-daemon as those should never be able to connect to the
host's busses.
dbus-daemon does NSS name look-ups in order to enforce its bus policy. This
might dead-lock if an NSS module use wants to use D-Bus for the look-up itself,
like our nss-systemd does. Let's work around this by bypassing bus
communication in the NSS module if we run inside of dbus-daemon. To make this
work we keep a bit of extra state in /run/systemd/dynamic-uid/ so that we don't
have to consult the bus, but can still resolve the names.
Note that the normal codepath continues to be via the bus, so that resolving
works from all mount namespaces and is subject to authentication, as before.
This is a bit dirty, but not too dirty, as dbus daemon is kinda special anyway
for PID 1.
This adds the boolean RemoveIPC= setting to service, socket, mount and swap
units (i.e. all unit types that may invoke processes). if turned on, and the
unit's user/group is not root, all IPC objects of the user/group are removed
when the service is shut down. The life-cycle of the IPC objects is hence bound
to the unit life-cycle.
This is particularly relevant for units with dynamic users, as it is essential
that no objects owned by the dynamic users survive the service exiting. In
fact, this patch adds code to imply RemoveIPC= if DynamicUser= is set.
In order to communicate the UID/GID of an executed process back to PID 1 this
adds a new "user lookup" socket pair, that is inherited into the forked
processes, and closed before the exec(). This is needed since we cannot do NSS
from PID 1 due to deadlock risks, However need to know the used UID/GID in
order to clean up IPC owned by it if the unit shuts down.
This makes it easier to discern the relevant and obsolete parts of the vtables,
and in particular helps when comparing introspection data with the actual
vtable definitions.
This adds "systemd-mount" which is for transient mount and automount units what
"systemd-run" is for transient service, scope and timer units.
The tool allows establishing mounts and automounts during runtime. It is very
similar to the usual /bin/mount commands, but can pull in additional
dependenices on access (for example, it pulls in fsck automatically), an take
benefit of the automount logic.
This tool is particularly useful for mount removable file systems (such as USB
sticks), as the automount logic (together with automatic unmount-on-idle), as
well as automatic fsck on first access ensure that the removable file system
has a high chance to remain in a fully clean state even when it is unplugged
abruptly, and returns to a clean state on the next re-plug.
This is a follow-up for #2471, as it adds a simple client-side for the
transient automount logic added in that PR.
In later work it might make sense to invoke this tool automatically from udev
rules in order to implement a simpler and safer version of removable media
management á la udisks.
link_messages is used during link configuration to advance the link
state machine through SETTING_ADDRESSES -> SETTING_ROUTES -> CONFIGURED.
If a route expires in the middle of this, it is possible for
link_messages to hit zero inside route_expire_callback, rather than in
route_handler or address_handler where it would trigger the next step in
configuration. Should this happen, the link will not complete
configuration, and it may not have its static routes configured.
Since route_expire_callback does not need to do anything once the
expired route has been removed from the kernel, it is safe to simply not
account for the netlink request.
Currently, systemd uses either the legacy hierarchies or the unified hierarchy.
When the legacy hierarchies are used, systemd uses a named legacy hierarchy
mounted on /sys/fs/cgroup/systemd without any kernel controllers for process
management. Due to the shortcomings in the legacy hierarchy, this involves a
lot of workarounds and complexities.
Because the unified hierarchy can be mounted and used in parallel to legacy
hierarchies, there's no reason for systemd to use a legacy hierarchy for
management even if the kernel resource controllers need to be mounted on legacy
hierarchies. It can simply mount the unified hierarchy under
/sys/fs/cgroup/systemd and use it without affecting other legacy hierarchies.
This disables a significant amount of fragile workaround logics and would allow
using features which depend on the unified hierarchy membership such bpf cgroup
v2 membership test. In time, this would also allow deleting the said
complexities.
This patch updates systemd so that it prefers the unified hierarchy for the
systemd cgroup controller hierarchy when legacy hierarchies are used for kernel
resource controllers.
* cg_unified(@controller) is introduced which tests whether the specific
controller in on unified hierarchy and used to choose the unified hierarchy
code path for process and service management when available. Kernel
controller specific operations remain gated by cg_all_unified().
* "systemd.legacy_systemd_cgroup_controller" kernel argument can be used to
force the use of legacy hierarchy for systemd cgroup controller.
* nspawn: By default nspawn uses the same hierarchies as the host. If
UNIFIED_CGROUP_HIERARCHY is set to 1, unified hierarchy is used for all. If
0, legacy for all.
* nspawn: arg_unified_cgroup_hierarchy is made an enum and now encodes one of
three options - legacy, only systemd controller on unified, and unified. The
value is passed into mount setup functions and controls cgroup configuration.
* nspawn: Interpretation of SYSTEMD_CGROUP_CONTROLLER to the actual mount
option is moved to mount_legacy_cgroup_hierarchy() so that it can take an
appropriate action depending on the configuration of the host.
v2: - CGroupUnified enum replaces open coded integer values to indicate the
cgroup operation mode.
- Various style updates.
v3: Fixed a bug in detect_unified_cgroup_hierarchy() introduced during v2.
v4: Restored legacy container on unified host support and fixed another bug in
detect_unified_cgroup_hierarchy().
Currently in the journal you get messages without context like:
systemd-sysv-generator[$pid]: Failed to build name: Invalid argument
When parsing the init script, show the file and line number where the
error was found. At the same time, add more context information if
available.
Thus turning the message into something like:
systemd-sysv-generator[$pid]: [/etc/init.d/root-system-proofd:13] Could not build name for facility $network,: Invalid argument
If journals get into a closed state like when rotate fails due to
ENOSPC, when space is made available it currently goes unnoticed leaving
the journals in a closed state indefinitely.
By calling system_journal_open() on entry to find_journal() we ensure
the journal has been opened/created if possible.
Also moved system_journal_open() up to after open_journal(), before
find_journal().
Fixes https://github.com/systemd/systemd/issues/3968
If no result parameter is provided, do not attempt to write the
found/newly-created route to it. This is presently not an issue as all
callers currently provide a non-NULL result parameter, however we should
do this for symmetry with address_add and future code robustness.
A following patch will update cgroup handling so that the systemd controller
(/sys/fs/cgroup/systemd) can use the unified hierarchy even if the kernel
resource controllers are on the legacy hierarchies. This would require
distinguishing whether all controllers are on cgroup v2 or only the systemd
controller is. In preparation, this patch renames cg_unified() to
cg_all_unified().
This patch doesn't cause any functional changes.
core: add cgroup CPU controller support on the unified hierarchy
(zj: merging not squashing to make it clear against which upstream this patch was developed.)
It is useful to look at a (possibly inactive) container or other os tree
with --root=/path/to/container. This is similar to specifying
--directory=/path/to/container/var/log/journal --directory=/path/to/container/run/systemd/journal
(if using --directory multiple times was allowed), but doesn't require
as much typing.
